1. Field of the Invention
This invention relates to a respiratory mask, more particularly to a respiratory mask for a continuous positive airway pressure (CPAP) machine.
2. Description of the Related Art
An effective way of treating obstructive sleep apnea is to use a continuous positive airway pressure (CPAP) machine. A person suffering from obstructive sleep apnea wears a respiratory mask that is connected to a pump of the machine during his/her sleep. The pump is controlled by a pressure adjustment main unit to continuously pump air into the user's airway to produce a continuous positive airflow, so that the user's airway may remain open and unblocked.
Referring to FIG. 1, a currently available respiratory mask 9 for a CPAP machine is shown to include a mask body 91, a forehead support 93, a forehead pad 94, and a head strap 95. The mask body 91 has a cushion pad 911 covering the user's nose and mouth, and a connecting hole 912 connected fluidly to an air supply tube 92. The air supply tube 92 is connected to a pump (not shown) for supply of a continuous positive pressure airflow into the mask 9. The mask body 91 further has left and right lug portions 913 (only one is visible) projecting respectively from left and right sides thereof and provided respectively with lower positioning holes 9131 (only one is visible). The forehead pad 94 is connected to a top end of the mask body 91 through the forehead support 93, and has two opposite upper positioning holes 941 (only one is visible). Four end portions 951 (only two are visible) of the head strap 95 are inserted respectively through the upper and lower positioning holes 941, 9131, and are then folded back to fix upon themselves through the use of hook and loop fasteners. In this state, the mask body 91 covers tightly the user's nose and mouth, and the forehead pad 94 abuts against the user's forehead. Hence, the pressure of wearing the mask 9 is distributed to the user's forehead and around the users nose and mouth to minimize discomfort during use of the mask 9.
However, due to the different facial dimensions of users, and due to the fact that the forehead support 93 is hard and is not adjustable, in some instances, the cushion pad 911 and the forehead pad 94 do not simultaneously and respectively abut against the user's forehead and the user's nose and mouth, so that the pressure cannot be effectively distributed to the user's forehead and the user's nose and mouth. Further, since the four end portions 951 of the head strap 95 must extend through the respective upper and lower positioning holes 941, 9131 and be folded back to fix upon themselves, the fixing operation of the head strap 95 is troublesome and cannot be quickly accomplished. In a case where the user must get up in the middle of the night to go to the toilet, the light must be switched on in order to remove the mask 9 and put it on again. This is not only troublesome, but may make it difficult for the user to fall back to sleep.